Guide shell for rock drills



March 26, 1935. J C -rig 1,995,535

GUIDE SHELL FOR ROCK DRILLS Filed Nov. 19, 1951 Z Z I J 50 /7 32 /6 5/ 34 2 Z2 j; 20 /4 /Z Z 5 JOHN c, cule775 INVENTOR ATTORNEY Patented Mar. 26, 1935 UNITED S AT GUIDE SHELL ronnoox mtrLLs John 0. Curtis, Cleveland, hio, assignor to The Cleveland Rock Drill 'Compan'y, Cleveland; j a Ohio; a corporation of 0hio 1 J Applicatioiimv mbsr L19, 1931 ..S fi 4 7 3 Claims.- (c1. 308 v I a guide shell and consequently reducing thecost' of operation. u

Another object of this inventionis toconstruct 10 a guide shelland a rock drill therefor whereby the exposed wearing surfaces of saidtguide-shell may be constantly subjected to the action of motive fluid, thus blowing and cleaning such. surfaces of any abrasive material which may be 7 Another object of this inventionis' to manufacture a guide shell and a rock drill therefor with lubricating means for the wearing surfaces thereof, thus resisting the deleterious effects ofattri- 'tion and consequently prolonging the life of the machine. a

Other objects and advantages more or less an cillary to the foregoing and the manner in which the various objects are attained reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification, in the claims of which there are assembled certain specific combinations of parts and specific constructions indicative of the scope and spirit of the invention.

In the drawing:

Fig. l is a longitudinal view of a rock drill mounted within its guide shell which is shown partly in section to illustrate the invention.

Fig. 2 is a cross sectional view taken on a plan indicated by line 2-2 in Fig. 1.

Referring to the drawing in which like symbols designate corresponding parts throughout the several views, the body of the shell 10 may be substantially of the usual form comprising a cradle 11 having side walls l2 and carrying a mounting cone 13. The side walls 12 are formed with a slot or guide-Way 14 extending the full length of the shell, said guide-way being formed with a lower or supporting surface 15 and an upper surface 16. The upper end of the shell is machined to form with the guide-way upper surface 16 a guide 17 having an upper finished surface 18. The rock drill cylinder 19 is provided with a pair of guides 20 extending the full length thereof and having lower surfaces 21 and upper surfaces 22. The lower'surfaces 21 are capable of V engagement with the shell supporting surfaces 15. Similarly extending the full length of deposed thereupon during the drillingoperationl vthev cylinder, :there isaxpair of slots or. guide.- Waysf23 with the 'upper'faces'24'engageable with the upper endof theshell or surfaces 18; c 'Itsis vobvious that when the cylinder '19 is first introduced within the, shell lily-the cylinder; surfaces 51.15 V

21 may rest upon the shell supporting-surfaces :15 affording a slight vclearance between the surfaces 24 and 18, or the oppositewaytakeplace;i: esthe cylinder ,surfaces24 mayrest uponth'elshellsurfaces 18,'and consequentlyaifording a slight clear; 10 ance between the-surfaces 15 ,and 21.1 However after the assembly has been:inioperationffor 'a relatively short time, the, wear-occurring upon said surfaces through the vibratory: impulse imparted to the cylinder 19-and' by its'lo'ngitudina'l l5 displacementj within the shell 10 will ibesequally divided among the wearing-surfaces 15 and. 21' :as well as 16' and 22. Heretoforethe .typeio'f :shell commonly-used would provide only a'rpair. of wear:-

ing surfaces as. forrinstance. surfaces :15.v and 21', 20

the upper end of the shelll8'being in spaced relation with the cylinder 19thus requiring a con--" stant replacement of expensive parts such as the cylinder 19 or shell 10 which would wear after a. V relatively short period of service. It will be seen 25 that with thisnew construction, the life of either the cylinder or the shell or both will necessarily be much longer than the life of an assembly affording only onepair of wearing surfacessimilar to the surfaces 15 and 21. 7

To allow the reciprocation of the working pis-- ton Within the cylinder l9.- such cylinder is pro: vided with an exhaust groove 25 connected to atmosphere through an exhaust passage 26. This construction is commonly used in machines of 35 this type and not intended'to form any part of 1 this invention, no further description of same is therefore necessary.

Extending the full length of the cylinder 19 and adjacent the fiat surfaces 24,-there is a pair 0 of ports 27 in constant registration with the exhaust groove 25 through radially disposed orifices 28. Leading from the ports 28 to the fiat surfaces 24, the cylinder is provided with a plurality of restricted passages 29 disposed in spaced relation substantially the full length of the cylinder, and adapted for constant registration with a restricted groove 30 disposed longitudinally on the guide shell upper surface 18 and opening to atmosphere on each end thereof, Leading from 50 said groove 30 to a similar groove 31 disposed on the upper surface of the cylinder guides 1 1, there is a plurality of equally spaced and restricted apertures 32 and from said groove 21 to a groove 33similarly disposed uponthe lower face 21 of 'tive fluid supply line.

the cylinder guide 14, there is a plurality of equally spaced apertures 34.

During the'reciprocation of the working piston within the cylinder 19, after each forward and backward movement of the piston, motive fluid will be admitted to the groove to exhaust to atmosphere through port 26. A certain amount of motive fluid however will escape through the orifices 28 ports 27, restricted passages 29 into the grooves 30 to atmosphere by the ends of said grooves not covered by the cylinder surfaces 24' and consequently blowing or cleaning any abrasive material which may have been deposed upon the guide shell upper surfaceduring the drilling operation. Motive fluid escaping from the cylinder 19 is constantly mixed or charged with lubricant which is generally furnished thereto by means of a line lubricator incorporated'withinthe mo- Such lubricant is consequently'mingled with the motive fluid to lubricate the different working of parts of the rock drill and will consequentlybe mingled with the motive fluid escaping through the orifices 28; It will also be carried to the upper surface 18 of the guide shell 10 as explained above thus lubricating V the wearing surfaces 18 and 24. From the groove 30, the lubricant mingled with the escaping motive fluid will finally find its way between the surfaces'15 and 21 through restricted apertures 32, groove 31, restricted apertures 34 and grooves 33 thus affording a positive lubrication system between the wearing surfaces 15 and 21, and 18 and Although the foregoing description is necessari- 1y of a detailed character to completely set forth the invention, it is to be understood that the specific terminology employed is not intended to be restrictive or confining, the motive fluid for instance furnished to the ports 27 could justas well be furnished thereto from the source of supply,

the arrangement of the grooves and ports could also be modified without departing from the scope and spirit of the invention as herein claimed.

I claim: Y

1. In a fluid actuated rock drill, the combination of a cylinder, of a carriage for said cylinder formed with surfaces upon which said cylinder is free to slide, an exhaust groove within said cylinder, and means including passages leading from said exhaust groove for admitting exhausting fore the passage of said cylinder thereon.

2. In a fluid actuated rock drill, the combination of a cylinder, of a'carriage for said cylinder formed with surfaces upon which the latter is freeto slide, means for exhausting the pressure fluid admitted into said cylinder comprising a groove in constant communication with the atmospheregthrough an exhaust port, and means for cleaning said surfaces before the passage of said cylinder thereon comprising additional ports leading from said exhaust groove for admitting exhausting fluid to said surfaces at both ends of said "cylinder. V

3. In a fluid actuated rock drill, the combination of a cylinder. having guides integral there'- with, of a carriage formed with guide-ways havv fluid to the middle portion of said surfaces bea ing upper and lower surfaces upon which said 

